PARTICIPATORY GIS: EXPERIMENTATIONS FOR A 3D SOCIAL VIRTUAL GLOBE
M. A. Brovelli, M. Minghini, G. Zamboni
Politecnico di Milano, DICA, Laboratorio di Geomatica, Como Campus, via Valleggio 11, 22100 Como, Italy - maria.brovellipolimi.it, marco.minghinipolimi.it, giorgio.zambonipolimi.it
Commission IV, WG IV5
KEY WORDS: GIS, Mobile, PGIS, Services, Three-dimensional, Virtual globe, Web based ABSTRACT:
The dawn of GeoWeb 2.0, the geographic extension of Web 2.0, has opened new possibilities in terms of online dissemination and sharing of geospatial contents, thus laying the foundations for a fruitful development of Participatory GIS PGIS. The purpose of the
study is to investigate the extension of PGIS applications, which are quite mature in the traditional bi-dimensional framework, up to the third dimension. More in detail, the system should couple a powerful 3D visualization with an increase of public participation by
means of a tool allowing data collecting from mobile devices e.g. smartphones and tablets. The PGIS application, built using the open source NASA World Wind virtual globe, is focussed on the cultural and tourism heritage of Como city, located in Northern
Italy. An authentication mechanism was implemented, which allows users to create and manage customized projects through cartographic mash-ups of Web Map Service WMS layers. Saved projects populate a catalogue which is available to the entire
community. Together with historical maps and the current cartography of the city, the system is also able to manage geo-tagged multimedia data, which come from user field-surveys performed through mobile devices and report POIs Points Of Interest. Each
logged user can then contribute to POIs characterization by adding textual and multimedia information e.g. images, audios and videos directly on the globe. All in all, the resulting application allows users to create and share contributions as it usually happens
on social platforms, additionally providing a realistic 3D representation enhancing the expressive power of data.
1. INTRODUCTION
Paradigms for publishing geographic information over the Web have radically changed in the last decades. The collection of
services related to online fruition of geospatial information, defined by Scharl and Tochtermann 2007 as the Geospatial
Web, has experienced such a revolution that the term GeoWeb 2.0 was coined to define it. According to Maguire 2007, this
new model represents nothing but the geographic extension of the wider overturn of Web nature known as Web 2.0 O’Reilly,
2005. The concept provides a clear explanation of the current, innovative generation of Internet applications characterized by
an unprecedented user interaction in terms of disseminating and sharing contents.
In turn, the advent of GeoWeb 2.0 proved to be a fertile ground for a new, incredible development of the so-called Participatory
GIS PGIS. The term was initially introduced in the mid-1990s to stress the social role of GIS as a tool for promoting public
intervention in decision-making processes Sieber, 2006. Aside from the rise of Web technologies, an additional impulse for
PGIS development was recently brought by the massive spread of mobile devices, which are equipped with sensors e.g. a GPS
receiver and a camera to geo-tag multimedia contents, and a non-stop Internet connection to immediately Web-publish them.
In this context, PGIS applications are rapidly evolving towards Web-based, community-shared platforms in which users are
able to manage their own data and, according to the paradigm of neogeography Turner, 2006, to also create customized mash-
ups from multiple sources of geographic information. As a result of PGIS historical evolution, available researches
prove to be highly heterogeneous in terms of both the PGIS investigated aspect and the related technologies. While a
number of studies is focussed on PGIS motivation and its social and critical role e.g. Elwood, 2006, recent years have seen an
exponential growth of attention on PGIS software development. Anyway, although some attention has been given to both GIS
applications somehow promoting public participation e.g. Hall et al., 2010 and field-data collection using mobile devices e.g.
Burke et al., 2006, a couple of considerations can be inferred. First, few academic research has studied the implementation of
participatory systems able to address the problem of entirely managing data from its collection in situ to its Web-publication.
In addition, literature is almost silent about PGIS applications involving user data interaction also in the third dimension.
Against this background, the purpose of the study is to build up a Web-based, participatory system able to: a allow citizens to
perform field surveys using common mobile devices, compiling and submitting ad hoc questionnaires together with multimedia
contents e.g. images, which are registered through the mobile device sensors and then georeferenced through the device
positioning services e.g. the GPS; b store and manage field- captured data into a spatial database and provide Web
publication using standard protocols; and c build up a Web- based system offering not just a 3D visualization interface, but
also an overall framework allowing users to manage data and create customized maps.
The proposed architecture was exploited for the creation of a PGIS application focussed on the report of cultural and touristic
Points Of Interest POIs of Como city, located in Northern Italy. Besides showing the extension of PGIS applications to the
third dimension, the results should also provide support for using the system in circumstances characterized by the need of
real-time, field-collected data e.g. emergency management. The paper is divided into four parts. First, it reviews the existent
literature relevant to PGIS development as a consequence of the Web 2.0 revolution. Next, system architecture is presented in
detail and the attention is focussed first on the issue of field- data collection through mobile devices, then on the applications
Volume XL-2W2, ISPRS 8th 3DGeoInfo Conference WG II2 Workshop, 27 – 29 November 2013, Istanbul, Turkey
This contribution has been peer-reviewed. The peer-review was conducted on the basis of the abstract. 13
used for implementing a participatory system with 3D content visualization. The paper concludes with a summary of the
study’s contributions and directions for future research.
2. BACKGROUND
